I backed this pretty much the instant it was announced. The first thing to know is that it’s much larger in scope than the original games, while keeping the NES-style visuals and interface. There are also callbacks to Deja Vu, Uninvited, and other titles. It really does seem to be shaping up to feel like a true sequel, with the writing front and center.
It also seems to be a do-over of the TurboGrafx CD game of the same name: some similar story elements, but not the same plot.
That game was decently well-reviewed but never felt like a true sequel, since it was an example of first-sequel experimentation: it swapped the first-person dungeon crawler perspective and writing for a point-and-click adventure perspective with very little writing. More like Zelda 2 in variation from the original than Mario 2 (USA).